JPS60155948A - Inspection method and apparatus by nuclear magnetic resonance - Google Patents

Abstract

PURPOSE:To perform the recording of data at a high speed, by forcibly returning magnetization to a thermal equilibrium state after a series of scannings to shorten a stand- by time. CONSTITUTION:In order to generate nuclear magnetic resonance to the atomic nucleus of the atom forming the structure of an object to be examined, said object to be examined is excited by a magnetic field in a Z-direction through a static magnetic field control circuit 2 and a static magnetic field coil 1, and a magnetic field through an exciting coil 5 by the 90 deg. pulse from an oscillator 6. Subsequently, a nuclear magnetic resonance signal due to a two-dimensional magnetic gradient through a gradient magnetic field control circuit 4 and a gradient magnetic field coil 3 is detected by a detection coil 8 and a series of scannings are finished. Succeedingly, a second 90 deg. pulse is applied to the coil 5 and the magnetic field in the Z-direction is applied to direct magnetism upwardly and a homogeneity spoil pulse is applied to the coil 3. Whereupon, magnetism is forcibly made thermally equilibrium and a magnetism vector coincides with a static magnetic field direction. By this mechanism, the correlation with the next sequence is eliminated and the next scanning can be started directly and data recording is performed at a high speed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field to which the invention pertains] The present invention relates to nuclear magnetic resonance
icresonance), (hereinafter referred to as rNMRJ)
It is abbreviated as.

) An NMR imaging device particularly suitable for medical equipment, which relates to an examination method and apparatus using nuclear magnetic resonance that uses phenomena such as the distribution of specific atomic nuclei within a subject to be known from outside the subject. Regarding improvements.

[Prior Art] First, an outline of the principle of NMR will be explained.

The atomic nucleus consists of protons and neutrons, which are considered to be rotating as a whole with a nuclear spin angular momentum I.

Figure 1 shows a hydrogen nucleus (one day).As shown in (a), it consists of one proton p, and the spin quantum number is 1.
It has a rotation expressed as /2.

Here, since the proton p has a positive charge e+ as shown in (b), the magnetic moment μ follows the rotation of the atomic nucleus.
occurs. In other words, each hydrogen nucleus can be thought of as a small magnet.

Figure 2 is an explanatory diagram that schematically shows this point. In a ferromagnetic material such as iron, the directions of these micromagnets are aligned as shown in (a), and magnetization is observed as a whole. . On the other hand, in the case of hydrogen, etc., the direction of the micromagnets (the direction of the magnetic moment) is random as shown in (b),
No magnetization is seen as a whole.

Here, for such a substance, static in two directions! & When a field of 1° is applied, each atomic nucleus aligns in the HO direction. That is, the energy unit of the nucleus is magnetized by m in the Z direction.

Figure 3 (a) shows this situation for a hydrogen nucleus. Since the spin quantum number of a hydrogen nucleus is 1/2, as shown in Figure 3 (b), -1/ 2 & + 1/
It is divided into two energy units of 2. The energy difference ΔE between two energy levels is expressed by equation (1).

ΔE-γ1'% Ho...(1) where γ is the gyromagnetic ratio h=h/zπ h is a blank constant Here, each atomic nucleus is subjected to a force due to the static magnetic field Ho, so the atomic nucleus moves along the Z-axis It precesses at an angular velocity ω as shown in equation (2).

ω = γHo (Larmor angular velocity)... (2) When an electromagnetic wave (usually a radio wave) with a frequency corresponding to the angular velocity ω is applied to a system in this state, resonance occurs, and the atomic nucleus has an energy difference shown by equation (1). It absorbs energy corresponding to ΔE and transitions to a higher energy unit. Even if several types of atomic nuclei with nuclear spin angular momentum coexist, each nucleus has a different gyromagnetic ratio γ, so the resonant frequencies differ, so it is possible to extract only the resonance of a specific atomic nucleus. Furthermore, by measuring the strength of the resonance, it is possible to determine the amount of nuclei present. Furthermore, after resonance, the atomic nucleus excited to a higher unit returns to a lower unit after a time determined by a time constant called relaxation time.

This relaxation time is the spin-lattice relaxation time (longitudinal relaxation time)
It is classified into Tl and spin-spin relaxation time (transverse relaxation time) 72, and data on material distribution can be obtained by observing this relaxation time. Generally, in solids, spins are almost fixed at fixed positions on the crystal lattice, so interactions between spins are likely to occur. Therefore, the relaxation time - 2 is short, and the energy obtained by nuclear magnetic resonance is
First, we move to spin systems and then to lattice systems.

Therefore, time T1 is significantly larger than T2. On the other hand, in a liquid, molecules move freely, so energy exchange between spins and between spins and the molecular system (lattice) is about the same. Therefore, times T+ and T2 have approximately equal values. In particular, the time T1 is a time constant that depends on the way each compound binds, and it is known that the value differs greatly between normal tissues and malignant tumors.

Here, we have explained hydrogen nuclei (11-1>), but it is possible to perform similar measurements with other nuclei that have nuclear spin angular momentum. It is applicable to carbon nuclei ('C), sodium nuclei (,"N a ), fluorine nuclei (19F), oxygen nuclei ("O), etc.

In this way, NMR can measure the presence (abundance) of specific atomic nuclei and their relaxation time, so by obtaining various chemical information about specific atomic nuclei within a substance, it is possible to conduct various tests within a subject. It can be carried out.

Conventionally, as an inspection device using NMR, this method uses the same principle as XmCT to excite protons in a virtual cross section of the subject and generates NM corresponding to each projection.
There is a method in which the R resonance is measured in many directions of the subject and the NMR resonance signal intensity at each position of the subject is determined by a reconstruction method.

FIG. 4 is an operational waveform diagram for explaining an example of an inspection method in such a conventional device.

The subject is first exposed to two gradient magnetic fields Gz+ as shown in Figure 4 (A) and a narrow frequency spectrum f as shown in (A).
RF pulse (90° pulse) is applied. in this case,
Protons only on the surface where the Larmor angular velocity ω = γ (Ho + ΔGz) are excited, and the magnetization M changes as shown in Fig. 5 (
If it is shown on a rotating coordinate system rotating at an angular velocity ω as shown in a), the direction is changed by 90° in the y'-axis direction. Unifiedly, as shown in Figure 4 (c) and (d), an X gradient magnetic field Gx and a y gradient magnetic field Gy are applied, thereby creating a two-dimensional gradient magnetic field, and in (bo), an NMR resonance signal as shown is generated. Detect. Here, the magnetization M is as shown in Figure 5 (b),
Due to the non-uniformity of the magnetic field, it gradually disperses in the direction of the arrow in the xLy' plane, so the NMR resonance signal eventually decreases and disappears after the Ts time, as shown in Figure 4 (e). . If the NMR resonance signal obtained in this way is subjected to Fourier transformation, it becomes a projection in the direction perpendicular to the gradient magnetic field synthesized by the X gradient magnetic field G x %y gradient magnetic field Gy.

Thereafter, after waiting for a predetermined time Td, the next sequence is repeated in the same manner as described above. In each sequence, G x S and G y are changed little by little.

This allows NMR resonance signals corresponding to each projection to be determined in many directions of the object.

By the way, in the conventional apparatus that performs such an operation, as shown in FIG. 4, the time Ts until the NMR resonance signal disappears is 10 to 20 mS, but the predetermined time Td until moving to the next sequence is is 1s due to relaxation time T1
ec 4! j! degree is required. Therefore, if a cross-section of a single object is to be reconstructed using, for example, 128 projections, the measurement requires a long time of at least 2 minutes, which is one of the major obstacles to achieving high speed. It is one.

[Object of the Invention] In view of the above, the object of the present invention is to observe a large number of echo signals due to magnetic field reversal, and then force the magnetization to return to a thermal equilibrium state, thereby achieving a high-speed An object of the present invention is to provide an inspection method and apparatus using NMR that can record data on a computer.

[Summary of the Invention] In order to achieve such an object, the present invention includes a step of applying a first 90° pulse to generate nuclear magnetic resonance in the nuclei of atoms constituting the tissue of a subject; 90°
A step of reversing the gradient magnetic field applied to the atomic nucleus multiple times after the application of the pulse and measuring the nuclear magnetic resonance signal generated at that time; This second step
Waiting for Tct time to elapse after application of the 90' pulse and then proceeding to the next step. At the same time, an image related to the tissue of the subject is regenerated based on the nuclear magnetic resonance signal. and a step of configuring.

[Example] The present invention will be described in detail below with reference to the drawings. FIG. 7 is a block diagram showing the configuration of an embodiment of a device for implementing the method of the present invention. In the same figure, 1 is a uniform magnetostatic hawk H
2 is a control circuit for the static magnetic field coil 1, which includes, for example, a DC stabilizing N source. The density of magnetic flux H generated by coil 1 is 0.1
It is desirable that T is about I, and that the uniformity is 1o-4 or more.

Reference numeral 3 generally indicates a gradient magnetic field coil, and 4 indicates a control circuit for this gradient magnetic field coil 3.

FIG. 6(A) is a configuration diagram showing an example of the gradient magnetic field coil 3, in which the 2-gradient magnetic field coil 31, the y-gradient magnetic field coil 32
．． 33. Although not shown, a y-gradient magnetic field coil 32.
It has the same shape as 33 and includes an X-gradient magnetic field coil that is rotated by 90°.

This gradient magnetic field coil generates a magnetic field having linear gradients in the x-, y-, and z-axis directions in the same direction as the uniform static magnetic field Ho. The control circuit 4 is controlled by a controller 20 (details will be described later).

Reference numeral 5 denotes an excitation coil that provides an RF pulse with a narrow frequency spectrum f as an electromagnetic wave to the subject, and its configuration is shown in FIG. 8 (b).

6 is the frequency corresponding to the NMR resonance condition of the atomic nucleus to be measured (for example, for protons, 42.6 MHz /
This is an oscillator that generates a signal of T), and its output is applied to a gate circuit 30' whose opening and closing are controlled by a signal from a controller 20 (details will be described later) and to an exciting coil 5 via a power amplifier 7. . Reference numeral 8 denotes a detection coil for detecting an NMR resonance signal in the subject, and its configuration is the same as the excitation coil shown in FIG. It is preferable that this detection coil be installed as close as possible to the subject, but it may also be used as an excitation coil if necessary.

9 is an amplifier for amplifying the NMR resonance signal obtained from the detection coil 8', 10 is a phase detection circuit, and 11 is a signal from a wave memory circuit 11 that stores the phase-detected waveform signal from the amplifier 9, for example, through an optical fiber. A computer inputs signals through a transmission line 12 and performs predetermined signal processing to obtain a tomographic image, and 14 is a display device such as a television monitor that displays the obtained tomographic image.

The controller 20 generates gradient magnetic fields Gz and Gx.

It is configured to be able to output the signals necessary to control Gy and modulation signals (analog signals) and the control signals (digital signals) necessary for transmitting RF pulses and receiving NMR signals. be.

FIG. 8 is a configuration diagram showing an example of such a controller, which is particularly capable of high-speed control and allows easy changes in control sequences and analog waveforms. In the same figure,
221 is a write control circuit for writing data sent from the console 210 or the computer 13 via the console into each memory; 222, 225, 228; 231 is a waveform storage memory in which the waveform data of the x, y, z gradient signal and modulation signal provided by the write control circuit are written, respectively; 223, 226, 229; 232 is this waveform storage memory 222. 225, 228. 231
latch circuits that temporarily hold the waveform data output from 224. 227. 230. 233 is this latch circuit 223. 226. 229. There is a DA conversion circuit that converts the output from 232 into DA. X21
V21Z21M2 is the DAA conversion circuit 224, 227
．． 230. x, y, respectively output from 233
z gradient signal output and modulation signal output.

234, 236. 238. 240 is a transmission/reception circuit control signal, that is, an AD conversion control signal, and a transmission gate control signal.

Reception gate control signal 9 Phase selection signal (This is a signal for selecting one type of pulse from among four types of R'F pulses with mutually different phases. However, here, only two types of RF pulses are used. waveform storage memories, 235, 237, 239, in which data of the selected and used) are written to the m write control circuit 221, respectively; 241 is this waveform storage memory 234. 236, 238. 2
A latch circuit that temporarily holds the data output from 40, T2
+82*R2, PSttctcl: (1) Latch circuit 235. 237. 239. These are an AD conversion control signal, a transmission gate control signal output, and a reception gate control signal output 1 phase selection signal output from 241. 243 is each waveform storage memory 222. ”225. 22
8. 231, 234. 236. 238. 24
a read control circuit for reading out the contents of 0 to the latch circuit; 2;
42 sets the value of the write/successive output start address from the console or computer (hereinafter simply referred to as "from the computer"); 244 is an output given from the computer; 244 is an output given from the computer; 244 is a memory address register that outputs the value +1 given from the write/continue control circuit as a write/continue address; An output count register 245 is set with the number of steps and notifies the readout control circuit 243 of the end of output, and an output count register 245 is set with the time length of one step given by the computer (1 step length) to generate a pulse of one step length. This is a long pulse generation circuit.

The operation of the controller having such a configuration is as follows.

(a) Write operation In the write operation, waveform data sent from the computer is written to a specified address in the waveform storage memory specified by the computer. That is, first, the memory address register 24
The write start address is set to 2. The data sent from the computer along with the write command is written to the address specified by the memory address register 242 in the waveform storage memory (for example, waveform storage memory 222) selected by the self-programming control circuit 221. After that, the write control circuit 221 automatically adds 1 to the memory address register 242 to make it the memory address for the next write. Data is sequentially written to other waveform storage memories by the same operation as described above.

(b) Readout operation In the readout operation, each memory is read out in parallel.J0 FIG. 9 shows an example of a time chart of readout signal waveforms. The computer first sets the reading start address of the waveform storage memory in the memory address register 242. Next, the number of read steps is set in the output count register 244. Further, one step length (time per one step during reading) is set in one step length pulse generation circuit 245. Next, the waveform storage memory 222 is numbered at the address indicated by the memory address register 242 in response to a reading start command from the computer. 225. 228. 231. 234
．． 236. The contents of 238°, 240, 238°, 240, . 232. 2
35. '237. 239. A latch pulse is output to 241 to latch the data. Next, 1 is added to the value of the memory address register 242.

Output Curran 1 - If register 244 indicates end;
From the read control circuit 243 to the latch circuit 223. 226
゜229, 232. 235. 237. 239.
A clear pulse is output to 241 to end the read operation. When the output count register 244 is not completed, it is 1 from the output count register 244 (subtract 1,
1 by the output from the step length pulse generation circuit 245.
The process moves to a tangent reading step that has the time length of the step. Thereafter, the same process can be repeated to read out a waveform as shown in FIG. 9, for example. X; y, z gradient signal X2. V2.
Z2 and the modulation signal M2 are output from the latch circuit and further sent to the DA converter 224. 227. 230. D in 233
This is an analog signal obtained by A conversion, and the modulated signal M2 is sent to the gate circuit 30 and also to the x and y signals.

The two gradient signals are each led to a control circuit 4 for the gradient magnetic field.

Since such a controller is equipped with dedicated hardware such as a waveform storage memory, it is possible to read and output a large amount of data at high speed. Furthermore, since the contents of the waveform storage memory can be rewritten as necessary, any analog or digital signal waveform can be output. Furthermore, it is easy to use part of the signal waveform (which is often actually used) by appropriately providing the read start address and the number of read steps.

The gate circuit 30 receives the signal from the oscillator 6, generates four types of signals having different phases by 90', selects one of the four types of signals based on instructions from the controller 20, and selects one of the four types of signals based on instructions from the controller 20. is further modulated with an RF modulation signal and the excitation coil 5
The detailed configuration is shown in Fig. 10 (only two of these types are used in the present invention).
. In the same figure, 311 is 90 where two signals with a phase shift of 0° and 90' are obtained with respect to the input RF multiplied signal.
° Phaser, 3.12. 323 is 1 that can simultaneously obtain two signals with a phase shift of 0° and 180° with respect to the input signal.
There is 80° phase shifter 1 and 90° phase shifter 311 as shown.
By giving each output of 180° to each of the 180° phase shifters, the outputs of
A signal with a phase difference of . These signals are respectively led to a combiner 321 through high frequency switches (for example, double balanced mixers: DBM can be used) 314 to 317, and the four signals are added. In this case, the high frequency switch is the decoder driver 3
The four outputs (X, Y, -X) of the decoder driver 320 are individually driven by the outputs of the decoder drivers 320 and 320, which are generated by decoding the phase selection signal PS given from the controller 20.

-Y), one of them becomes active. As a result, only the corresponding switch becomes conductive (the other 3
switches are non-conducting). Therefore, the coupler 321 has one
This results in only one signal being input.

The output of the coupler 321 is input to the direct modulator 323 via the amplifier 322, where the RF modulation signal (pulse signal) given by the controller 20 determines the rotation of the magnetization M by its pulse width and peak value.

), and is modulated into, for example, a Gaussian waveform shown in FIG. 4(A) and output.

According to the gate circuit having such a configuration, O', 90', 183 . It is extremely easy to obtain an RF multiplied signal exhibiting a phase difference of 270', selectively select a desired one from among these signals, and further modulate that signal with a desired waveform at an appropriate timing. There are advantages.

The operation of the apparatus of the present invention constructed in this way will be explained step by step with reference to FIG.

1) Selectively excite the subject with the first 90° pulse, G, and Z ((a) and (b) in FIG. 11). This generates an FID signal.

Apply magnetic fields Gx and Gy of magnitude gx++Q't/'+ for 2>tm+ time ((C) and Ayu (D) in Figure 11)
).

3) After that, the sign of the magnetic field is reversed so that the formula is satisfied for a time t'm1. This generates an echo signal.

gx+ ×Q' x+ <Q Qy+ XO'! /+ <Q 4) The echo signal reaches its maximum at the end of the t'm1 time. However, Qx+ Xl:m+ = C1' x+ Xi' m+
9y+ Xj+n+ = Q' y+ X'j' m,
+5) Repeat steps 2) to 4) n-1 times (n>1).

However, gxpX'jmp= Q'xpxt' mPCIyp
X'jmp=Q'ypxt' mPwhere n=1.
2. ,,,,n 6) At the maximum echo signal, add a second 90-pulse and 02 to turn the magnetization up.

7) Next, as shown in (b), (c), and (d) of Figure 11, homogeneity spoils are applied to Gx, Gy, and Gz.
Add pulses a, b, and c. This makes the magnetization vector static! ! It can be completely returned to the field direction and uncorrelated with the next sequence.

8) Wait for 'Td time and move on to the next sequence.

In the next sequence, steps 1) to 7) above are repeated.

In this way, a large number of NMR signals are obtained as echo signals, and at the same time, the following sequence is repeated with a short waiting time Td, and projections in many directions can be obtained in a short time. Additionally, averaging processing can be performed to improve image quality. The NMR signal obtained in this way is transferred to the wave memory 1.
1 to the =1 monitor 13, where a reconstructed image is obtained by image reconstruction calculation. The obtained image is displayed on the display 14
will be displayed.

Note that the present invention is not limited to the above embodiments,
It can be applied to the following various methods.

B> In the embodiment shown in FIG. 11, n=2 and Ox +
>>Q' x l'+ Qy + >>Q' y
+ +gX2 <<, Q'X24 CJy2<<C1'
y2Q' x+ =QX21 Cl' y+ =gy
12 under the conditions of 2.

Using the echo signals occurring during t'ml and tm2 periods, t
The signals generated during the ml and t' m2 periods are RF pulses and G
It is not used as measurement data because it is affected by switching noise, etc. from x, Gy, and Gz. 1 According to the above conditions, tml <<t' m+ and j1m
2>>t'm2, so the signal acquisition time is long<S/
It is possible to record N good signals.

) It can be applied to the spin warp method (Fig. 13). In this case, ikp (1) to 1.2. ,,.

, n) are constant, and Qxp (n=1.2., , n) is changed.

c) Can be applied to the Fourier method (Figure 13).

In this case, thmp (1) to 1.2. ,,.

n), and Qxp (n=1.2.,.

, n) are constant.

2) It can be applied to the echo planar method (Fig. 14).

e) It can be applied to the selective excitation line method (Figure 15).

) It can be applied to the inversion recovery method (Fig. 16).

g) A system that uses inter-image calculation to obtain -U, T+ images, T2 images, spin density images, and images that are a combination of these images.

H) It can be applied to a multi-slice method in which the waiting time of Td is used to excite other planes and information from them is obtained.

[Effects of the Invention] As described above, according to the present invention, since the magnetization is forcibly turned upward after a series of scans, it is possible to move to the next scan with a short waiting time Td. In addition, by reversing the magnetic field, a large number of echoes are generated in a short period of time. Therefore, the overall scanning time can be shortened.

Furthermore, since a large amount of data is tt'7 in a short time, signal averaging or averaging of multiple images can be performed, resulting in high quality images.

Furthermore, the homogeneity spoil pulse breaks the correlation between the previous and subsequent sequences, allowing the magnetization to move correctly.

In the case of the method shown in FIG. 12, echo signals are observed, so RF pulses, Gx, Gy.

The negative influence of Gz becomes extremely small. At the same time, useless Ts
+, T's2 is short and the signal is large.

Furthermore, the inter-image calculation method as described in (g) above has the advantage that an image suitable for the purpose can be easily obtained.

Further, if the multi-slice method is used, it is possible to achieve an apparently even higher speed.

[Brief explanation of the drawing]

Figure 1 is a diagram explaining the spin of a hydrogen atom, Figure 2 is a schematic diagram of the magnetic moment of a hydrogen atom, Figure 3 is a diagram illustrating the state in which the nucleus of a hydrogen atom is aligned in the direction of the magnetic field, FIG. 4 is a diagram showing an example of an inspection pulse waveform by conventional NMR, FIG. 5 is a diagram showing magnetization M on rotational coordinates, FIGS. 6 and 7 are configuration diagrams of an apparatus according to an embodiment of the present invention, and FIG. 9 is a structural diagram showing an example of a controller, FIG. 9 is an operation waveform diagram for explaining the operation according to the present invention, FIG. 10 is a diagram showing an example of a gate circuit, and FIG. 11 is a diagram showing a sequence according to the present invention. 12 to 16 are operational waveform diagrams for explaining other embodiments of the present invention. 100. Coil for static magnetic field, 2.4. ,,magnetic field control circuit,
301. Gradient magnetic field coil, 501. Excitation coil, 68
00 oscillator, 810. Detection coil, 10, Phase detection circuit, 11, Wave memory circuit, 13.
,,computer,20. ,. controller, 30. ,,gate circuit. Cause 1 (a) (0) Fig. 2 (a) (b)゛'□゛Leather 3 Fig. 4 Fig. 5 (a)

Claims (1)

[Claims] (1) Atoms constituting the tissue of the subject? a step of applying a first 90° pulse for causing nuclear magnetic resonance to the atomic nucleus; and a step of reversing the gradient magnetic field applied to the atomic nucleus multiple times after applying the 90° pulse, and the nuclei generated at that time; a step of measuring a magnetic resonance signal; a step of applying a second 90° pulse after the step of measuring the nuclear magnetic resonance signal; and waiting for Td time to elapse after application of the second 90° pulse. repeating the sequence including a waiting time for moving on to the next step, and reconstructing an image related to the tissue of the subject based on the nuclear magnetic resonance signal. Inspection method. (2) In the step of reversing the gradient magnetic field applied to the atomic nucleus multiple times after applying the 90° pulse and measuring the nuclear magnetic resonance signal generated at that time, one of the reversing magnetic fields is made stronger than the other. 2. The nuclear magnetic resonance testing method according to claim 1, wherein only the echo signal of the nuclear magnetic resonance signal generated thereby is observed. (3) reversing the gradient magnetic field applied to the atomic nucleus at least once after applying the 90° pulse and measuring the nuclear magnetic resonance signal generated at that time;
A patent claim characterized in that the gradient magnetic field to be applied is determined appropriately so that image reconstruction can be performed by any one of the two-dimensional PR method, the spin warp method, the echo planar method, or the selective excitation line method. The method for testing by nuclear magnetic resonance according to item 1. (C) In the step of applying the first 90° pulse, a 180° pulse for inversion recovery is applied prior to the first 90'' pulse. The nuclear magnetic resonance inspection method according to item 1. (5) In the step of applying the second 90'' pulse, a bomogenity spoil pulse is applied using a gradient magnetic field after the second 90° pulse. An examination method using nuclear magnetic resonance according to claim 1, characterized in that: (6) In the step of reconstructing an image related to the tissue of the subject based on the nuclear magnetic resonance signal, a T+ image or a T2 image or a spin density is calculated by performing an inter-image calculation from a plurality of images obtained by changing time parameters. Claim 1 characterized in that an image or a combination image thereof is obtained.
Inspection method using nuclear magnetic resonance as described in section. (7) Multi-slicing is carried out by selectively exciting other planes and obtaining plane information during the time period. Inspection method. (8) means for applying a high-frequency pulse to cause nuclear magnetic resonance in the nuclei of atoms constituting the tissue of the subject;
In the nuclear magnetic resonance signal inspection apparatus comprising means for measuring a nuclear magnetic resonance signal generated in the atomic nucleus, the means for applying the high frequency pulse applies a first 906 pulse, and after applying the 90'' pulse, the radio frequency pulse is applied. The gradient magnetic field applied to the atomic nucleus can be reversed multiple times, and the means for applying the high-frequency pulse is configured to apply a second 90'' pulse, wait for a predetermined time after that, and then move on to the next sequence. and further characterized in that the means for measuring the nuclear magnetic resonance signal generated in the atomic nucleus is configured to measure the nuclear magnetic resonance signal generated during the period in which the magnetic field applied in the reversed manner is applied. Inspection device using magnetic resonance.